Benefits of biomass heating

The use of biomass in heating systems is beneficial because it uses agricultural, forest, urban and industrial residues and waste to produce heat and electricity with less effect on the environment than fossil fuels. [1] This type of energy production has a limited long-term effect on the environment because of the carbon in biomass is part of the natural carbon cycle ; while the carbon in fossil fuels is not, and permanently adds carbon to the environment when burned for fuel ( carbon footprint ). [2] Historically, before the use of fossil fuels in significant quantities, biomass in the form of wood fuel provided most of humanity’s heating.

Drawbacks of biomass heating

Large scale, the use of biomass removes agricultural land from food production, reduces the carbon sequestration capacity of forests, and extracts nutrients from the soil. Combustion of biomass creates air pollutants and adds significant amounts of carbon to the atmosphere. [3]

Using biomass as a fuel Produces air pollution in the form of carbon monoxide , NOx (nitrogen oxides), VOCs ( volatile organic compounds ), particulates and other pollutants, In Some boxes at levels Above Those from traditional fuel sources Such as coal or natural gas . [4] [5] Black carbon – a pollutant created by incomplete combustion of fossil fuels, biofuels, and biomass – is possibly the second largest contributor to global warming. [6] In 2009, it was reported that it was largely controlled by fossil fuel burners. [7]Researchers measured a significant concentration of 14 C , which is associated with recent plant life rather than with fossil fuels. [8]

The carbon dioxide is released from the atmosphere as carbon dioxide (CO 2 ) . The amount of carbon stored in dry wood is approximately 50% by weight. [9] When from agricultural sources, plant matter can be replaced by planting for new growth. Where the biomass is from forests, the time to recapture the carbon storage capacity, and the carbon storage capacity of the forest may be reduced overall if destructive forestry techniques are employed. [10] [11] [12] [13]

The biomass-is-carbon-neutral proposal puts forward in the early 1990s that is more mature than ever before. When a tree’s carbon is released into the atmosphere in a single pulse, it contributes to climate change much more than woodland timber rotting slowly over decades. [14] Current studies indicate that “even after 50 years the forest has not recovered from its initial carbon storage” and “the optimal strategy is likely to be protected from the standing forest”. [15]

Biomass heating in our world

Biomass heating system in the Spanish Basque Country

The oil price increases since 2003 and increases the value of biomass for heat generation. Forest renderings, agricultural waste, and crops grown specifically for energy production become competitive with dense fossil fuels rise. Efforts to develop this potential may have the effect of regenerating mismanaged croplands and be a cog in the wheel of a decentralized, multi-dimensional renewable energy industry. Efforts to promote and advance these methods became common throughout the European Unionthrough the 2000s. In other areas of the world, inefficient and polluting means clustering to generate heat from biomass coupled with poor forest practices-have Significantly added to environmental degradation .

Buffer tanks

Buffer tanks store the hot water the biomass appliance and circulates it around the heating system. [16] Sometimes referred to as ‘thermal stores’, they are crucial for the efficient operation of all biomass boilers where the system loading fluctuates rapidly, or the volume of water in the complete hydraulic system is relatively small. The boiler supply is minimized by the boiler output. Rapid cycling of the boiler causes a large increase in harmful emissions such as Carbon monoxide , dust, and NOx, greatly reduces boiler efficiency and increases electrical consumption of the unit. In addition, service and maintenance requirements will be increased as well as increased cooling rates. Although most boilers claim to be able to turn down to 30% of nominal output, in the real world this is often not achievable due to differences in the fuel of the ‘ideal’ or test fuel. A suitably sized buffer tank should be considered to be the least important for the nominal output – in other words unless the biomass component is purely basic, the system should include a buffer tank. In any case where the secondary system does not contain sufficient water for the system must include a suitably sized buffer tank. TeaThe invention relates to a heat source of the combustion chamber and to the thermal mass of the combustion chamber. light weight, fast response boilers require only 10ltr / kW, while industrial wet wood units require 40ltr / kW. [17]

Types of biomass heating systems

Little biomass heating plant in Austria; the heat power is about 1000 kW

The use of Biomass in heating systems has many uses, and all have different uses. There are four types of heating systems that use biomass to heat a boiler. The types are Fully Automated, Semi-Automated, Pellet-Fired, and Combined Heat and Power.

Fully automated

Fully automated systems operate exactly how they sound. Chipped or ground up waste wood is brought to the site by delivery trucks and dropped into a holding tank. A system of conveyors then transports the wood from the holding tank to the boiler at a certain managed rate. This rate is managed by computer controls and a laser that measures the load of fuel the conveyor is bringing in. The system automatically goes on and off to maintain the pressure and temperature within the boiler. Fully automated systems offer a great deal of ease in their operation because they only require the operator of the system to control the computer, and the transportation of wood while offering comprehensive and effective solutions to complex industrial challenges. [18] [19]

Semi-automated or “surge bin”

Semi-Automated or “Surge Bin” systems are very similar to fully automated systems except they require more manpower to keep operational. They have smaller holding tanks, and a much simpler conveyor systems. The reasoning for the changes of the fully automated system is the efficiency of the system. The heat created by the combustor can be used to directly heat the air in a boiler system which acts as the medium by which the heat is delivered. [20]Wood fire fueled boilers are most efficient when they are running at their highest capacity, and the heat required for the year. Considering that the system will only need to be of high quality, it is made to meet the requirements for the majority of the year to maintain its high efficiency. [19]

Pellet-fired

The third hand type of biomass heating systems are pellet-fired systems. Pellets are a processed form of wood, which make them more expensive. They are more expensive, they are much more condensed and uniform, and therefore more efficient. Further, it is relatively easy to automatically feed pellets to boilers. In these systems, the pellets are stored in a grain-type storage silo, and gravity is used to move them to the boiler. The storage requirements are much smaller for pellet-fired systems because of their condensed nature, which also helps cut down costs. These systems are used for a wide variety of facilities, but they are most efficient and cost effective where they are limited and where the pellets are made fairly close to the facility. [19]

Agricultural pellet systems

They are capable of burning pellets with higher ash rate (paper pellets, hay pellets, straw pellets). One of this kind is PETROJET pellet burner with rotating cylindrical burning chamber. [21] In terms of efficiencies advanced pellet boilers can exceed other forms of biomass because of the more stable fuel charataristics. Advanced pellet boilers can even work in condensing mode and cool down combustion gases to 30-40 ° C, instead of 120 ° C before to the flue. [22]

Combined heat and power

Combined heat and power systems are used in the manufacture of wood chips , such as wood chips , is used to generate power, and is produced by the power generation system. They have a very high cost because of the high pressure operation. Because of this high pressure operation, the need for a highly trained operator is mandatory. Another drawback is that while they produce electricity they will produce heat, and if producing heat is not desirable for certain parts of the year, the addition of a cooling tower is necessary, and will also raise the cost.

There are certain situations where CHP is a good option. They would have a large supply of waste wood, and a need for both heat and power. Other places where these systems would be optimal hospitals and prisons, which need energy, and heat for hot water. These systems are sized so that they will produce enough heat to match the average heat load that is not needed. [19]

Jump up^ “Treetrouble: Testimonies on the Negative Impact of Large-scale Tree Plantations Prepared for the Sixth Conference of the Parties on the Convention on Climate Change” . Friends of the Earth International. Archived from the original on 26 July 2011 . Retrieved 11 August 2010 .